Influence of boundary conditions on the collapse behaviour of stiffened panels under combined loads

• Finite element analyses are conducted to investigate the influence of boundary conditions and geometry.
• Periodical symmetric and symmetric boundary conditions in the longitudinal direction are used.
• The ultimate strength of stiffened panels under combined biaxial thrust and lateral pressure is studied.
• The periodical symmetric boundary condition in the longitudinal direction is an appropriate model.

A series of finite element analyses are conducted to investigate the influence of boundary conditions and geometry of the model on the predicted collapse behaviour of stiffened panels. Periodic and symmetric boundary conditions in the longitudinal direction are used to calculate the ultimate strength of stiffened panels under combined biaxial thrust and lateral pressure. The calculated ultimate strength of stiffened panels are compared with those by different FEM (finite element method) code and are assessed. The periodic boundary condition in the longitudinal direction for two spans or bays model provides an appropriate modelling to a continuous stiffened panel and can consider both odd and even number of half waves and thus, is considered to introduce the smaller model uncertainty for the analysis of a continuous stiffened panel.